The invention relates to a bag filling and closing apparatus in which the material to be filled in is inserted into a prefabricated bag in a filling station, the apparatus including a spreading and holding device for the bags to prepare the bags for the filling process, with such device gripping the bags in a position next to the filling station, spreading them open, and moving them into the filling station.
U.S. Pat. No. 4,495,751 discloses a bag filling and closing apparatus which includes a rotatable disc disposed in a vertical plane. The disc is provided with openings which are distributed over its circumference. Around the openings, tubular holding devices are provided which project horizontally from a surface of the disc. A section of a tubular packaging material from a roll is pushed onto the tubular holding devices. The section is severed at one end and sealed. The disc rotates in the manner of a revolver and, in a subsequent station, the merchandise to be packaged is pushed through the respective opening into the interior of the tubular holding device.
Due to the use of a vertically arranged disc which is rotatable about a horizontal axis, this prior art apparatus can be employed only for relatively small packages. Some concerns also arise here regarding the proper operation of the apparatus since numerous moving parts must be accommodated within a small space.
Also known are bag filling devices in which a stack of individual bags is held available in the filling station and the respective upper bag is blown up or opened by vacuum suction. In a second movement, a filling orifice configured as a spreading device enters into the open container and thereafter the material to be filled in, for example a packet of toilet paper, is pushed into the bag. These devices are subject to malfunction since numerous moving elements are accommodated in close confines in the region of the filling station and interfere with one another during their motion sequences so that they often can be moved only consecutively. This leads to delays. Moreover, the material to be filled in must be pushed over a ramp into the respectively uppermost bag of the stack of bags. This results in numerous cases of malfunction (ski jump effect). A further drawback is that, in practice, the number of bags that can be accommodated in the filling position is limited to about 20 bags. This requires frequent replenishment of a stack of bags and thus frequent interruptions of operation.
Another prior art apparatus includes an integrated bag manufacture and assembly system in which the individual bags are brought into the filling station with the aid of a suction belt conveyor immediately upon completion of manufacture and are then opened by blowing in air or by suction. This method is also subject to malfunctions. Due to electrostatic or material specific adhesive forces, the bags cannot always be opened reliably. A synchronous supply is not always ensured.
Additionally, several special constructions are known which, however, have not yet been found to be a reliable and malfunction-free solution for all types of filling processes.